CN106598116A - Anti-condensation control method for power equipment box - Google Patents

Abstract

The present invention provides an anti-condensation control method for power equipment cabinets. By monitoring the temperature and humidity inside and outside the power equipment cabinets in real time and judging the situation of the external environment temperature in different regions, the current temperature error e and temperature error change ec are obtained. After fuzzy and calculation processing, the corresponding fuzzy sets of △Kp, △Ki, △Kd and Kp, Ki, Kd values are obtained. According to the Kp, Ki, Kd values, the PID control parameters are calculated to control the heater. Keep the difference between the current temperature T2 inside the cabinet and the temperature T1 outside the cabinet within a predetermined range. The embodiment of the present invention has the advantages of good anti-condensation effect, easy renovation, upgrading and maintenance.

Description

An anti-condensation control method for electric equipment box

technical field

The invention relates to the technical field of anti-condensation of electric equipment, in particular to an anti-condensation control method of an electric equipment box.

Background technique

In some areas (such as the subtropical monsoon climate zone), the air humidity is high at the turn of spring and summer. Due to the high humidity inside the equipment box in the substation, condensation is prone to occur, especially in outdoor terminal boxes. If the sealing is not tight, the temperature and humidity control measures are not appropriate, etc., the condensation phenomenon in the box is often prone to occur, resulting in creepage, flashover accidents, and sometimes the terminal box catches fire due to a short circuit, so the problem of condensation in the box is solved is very important.

In the prior art, two methods of heating-type dehumidification and semiconductor-type dehumidification are commonly used in the cabinet. These two methods have obvious defects, and the dehumidification effect is difficult to meet the demand. In addition, for technological upgrading and transformation, the existing equipment needs to be replaced as a whole, and the equipment needs to be powered off once, and the secondary wiring needs to be re-wired. The risk of accidental contact and miswiring during the transformation is relatively high.

Contents of the invention

The technical problem to be solved by the present invention is to provide an anti-condensation control method for an electric equipment box, which has a good anti-condensation effect and is easy to modify.

In order to solve the above technical problems, an embodiment of the present invention provides an anti-condensation control method for a power equipment box, including the following steps:

Obtain at least the temperature T2 inside the cabinet, the temperature T1 outside the cabinet and the humidity H2 inside the cabinet in real time through a variety of sensors;

Judging the situation of the external environment temperature in different regions, calculating and obtaining the current temperature error e and temperature error change ec according to the temperature T2 inside the cabinet and the temperature T1 outside the cabinet;

The temperature error e and the temperature error change ec are fuzzified to obtain the fuzzy set E corresponding to the temperature error e and the fuzzy set EC corresponding to the temperature error change ec, wherein the fuzzy set is Zhengda PB, Zhengzhong PM, One of positive small PS, zero Z, negative small NS, negative medium NM and negative large ND;

According to the temperature error fuzzy set E and the temperature error change fuzzy set EC, query the pre-generated △Kp law table, △Ki law table, △Kd law table, and obtain the fuzzy sets of △Kp, △Ki, △Kd, the said The fuzzy set of △Kp, △Ki, △Kd is one of positive big PB, positive middle PM, positive small PS, zero Z, negative small NS, negative middle NM and negative big ND;

Perform defuzzification calculations according to the fuzzy sets of ΔKp, ΔKi, and ΔKd to obtain Kp, Ki, and Kd values;

Calculate and obtain PID control parameters according to the Kp, Ki, and Kd values, and control the heater according to the PID control parameters, so that the difference between the current cabinet temperature T2 and the cabinet external temperature T1 remains within a predetermined range;

When the humidity H2 in the current cabinet is greater than a startup threshold, the compressor is controlled to start to dehumidify the inside of the terminal box.

Wherein, the temperature error e and the temperature error change ec are fuzzified, and the steps of obtaining the fuzzy set E corresponding to the temperature error e and the fuzzy set EC corresponding to the temperature error change ec are as follows:

According to the relationship between the actual domain of the temperature error e and the fuzzy universe, the input quantization factor ke is obtained, the actual value of the temperature error e is multiplied by the input quantization factor ke, the quantization input value of the temperature error e is obtained, and Fuzzy processing to obtain the corresponding fuzzy set E;

According to the relationship between the actual universe of the temperature error change ec and the fuzzy universe, the input quantization factor kec is obtained, and the actual value of the temperature error change ec is multiplied by the input quantization factor kec to obtain the quantized input value of the temperature error change ec , and perform fuzzy processing to obtain the corresponding fuzzy set EC.

Wherein, the fuzzification process is specifically as follows:

Obtain the corresponding fuzzy set E according to the membership function of the fuzzy subset corresponding to the temperature error e; or

According to the membership function of the fuzzy subset corresponding to the temperature error ec, the corresponding fuzzy set EC is obtained;

Wherein, the membership function is a trigonometric function or a Gaussian membership function.

Wherein, it further includes the step of generating the △Kp law table, △Ki law table, and △Kd law table in advance, wherein, E, EC, △Kp, △Ki, △Kd have the following mapping relationship:

E×EC→ΔKp×ΔKi×ΔKd

In the ΔKp rule table, ΔKi rule table, and ΔKd rule table, corresponding to each domain value of E and EC, the ΔKp, ΔKi, and ΔKd all have a definite domain value.

Wherein, according to the fuzzy sets of ΔKp, ΔKi, ΔKd, the steps of performing defuzzification calculation to obtain Kp, Ki, and Kd values are as follows:

Defuzzifying the fuzzy sets of ΔKp, ΔKi, and ΔKd to obtain corresponding domain values;

Multiply the domain value corresponding to △Kp, △Ki, △Kd by the quantization factor of the output variable to obtain the Kp, Ki, Kd value, and the output quantization factor is based on the actual domain of △Kp, △Ki, △Kd The relationship between fuzzy domain of discourse is obtained.

Wherein, the activation threshold is 50%, and the predetermined range is ±3°C.

Implement the present invention, have following beneficial effect:

The embodiment of the present invention provides an anti-condensation control method for a power equipment box, which can keep the temperature difference inside and outside the power equipment box within a predetermined range through the fuzzy control method, and at the same time perform dehumidification treatment in combination with the humidity in the cabinet, which can be very good It can effectively prevent the generation of condensation, and at the same time reduce the engineering quantity and risk of the transformation of the cabinet, and facilitate maintenance.

Description of drawings

Fig. 1 is a schematic diagram of the main flow of an embodiment of an anti-condensation control method for a power equipment box provided by the present invention;

Fig. 2 has shown the PID adjustment schematic diagram that the inventive method adopts;

Fig. 3 shows a schematic diagram of the membership function corresponding to the temperature error e in an embodiment of Fig. 1;

Fig. 4 is the tabular form corresponding to the degree of membership function in Fig. 3;

Fig. 5 shows a schematic diagram of the membership function corresponding to the temperature error change ec in an embodiment of Fig. 1;

Fig. 6 is the tabular form corresponding to the degree of membership function in Fig. 5;

Fig. 7 shows a schematic diagram of a ΔKp law table;

Figure 8 shows a schematic diagram of a ΔKi law table;

Fig. 9 shows a schematic diagram of a ΔKd law table;

Fig. 10 shows a detailed flowchart of an embodiment of an anti-condensation control method for a power equipment box.

detailed description

The present invention will be described in detail below in conjunction with the accompanying drawings.

As shown in FIG. 1 , it shows a schematic flow diagram of an embodiment of an anti-condensation control method for a power equipment box provided by the present invention. Please combine with FIG. 2 to FIG. 9, in this embodiment, the anti-condensation control method for the electrical equipment box includes the following steps:

Step S10, obtain the temperature T2 inside the cabinet and the temperature T1 outside the cabinet of the terminal box in real time through the temperature sensors installed inside and outside the power equipment box; obtain the humidity H2 inside the cabinet through the temperature sensor;

Step S11, judge the situation of the external environment temperature in different regions, calculate and obtain the current temperature error e and temperature error change ec according to the temperature T2 inside the cabinet and the temperature T1 outside the cabinet, where the temperature error e is the temperature inside the cabinet T2 The difference from the temperature T1 outside the cabinet, the temperature error change ec is the change value between the e obtained this time and the e obtained in the last measurement;

Referring to FIG. 2 , it shows the principle diagram of the PID adjustment adopted in the method; wherein, the fuzzy self-adjusting PID algorithm adopted in the method has only two inputs, the error and the change of the error. The system adds three fuzzy self-tuning PID parameters (proportional parameter Kp, integral parameter Ki, differential parameter Kd) before PID control, and the last three parameter changes are added to the initial value.

In the method of the present invention, it is necessary to judge whether the external environment temperature rises, falls, or is stable, and then operates under the anti-condensation temperature condition. It is understandable that condensation will occur if the temperature inside the electric cabinet is higher than that outside the cabinet in a large cooling environment or low temperature environment, and condensation will occur if the temperature inside the electric cabinet is higher than that outside the cabinet. Condensation will occur. Therefore, when the external ambient temperature rises (or in a high temperature state), it is generally required that the temperature inside the cabinet be higher than that outside the cabinet to prevent condensation; and when the external ambient temperature drops (or in a low temperature state), it is generally required that the temperature inside the cabinet is lower than that outside the cabinet. Only the temperature can prevent condensation. Therefore, according to different environments, different methods are used to calculate and obtain the current temperature error and temperature error change. For details, please refer to the steps in Figure 10.

Step S12, performing fuzzy processing on the temperature error e and temperature error change ec to obtain a fuzzy set E corresponding to the temperature error e and a fuzzy set EC corresponding to the temperature error change ec, wherein the fuzzy sets are Zhengda PB, One of positive middle PM, positive small PS, zero Z, negative small NS, negative middle NM and negative big ND;

Specifically, it includes: according to the relationship between the actual domain of the temperature error e and the fuzzy universe, the input quantization factor ke is obtained, and the actual value of the temperature error e is multiplied by the input quantization factor ke to obtain the quantization of the temperature error e Input the value and perform fuzzy processing to obtain the corresponding fuzzy set E; The optimization factor ke is 0.3.

According to the relationship between the actual universe of the temperature error change ec and the fuzzy universe, the input quantization factor kec is obtained, and the actual value of the temperature error change ec is multiplied by the input quantization factor kec to obtain the quantized input value of the temperature error change ec , and perform fuzzy processing to obtain the corresponding fuzzy set EC, for example, in an example, the actual domain ec∈[-5,5], the fuzzy domain ec∈[-3,3], then the input quantization at this time Because it is 0.6.

Obtain the corresponding fuzzy set E according to the membership function of the fuzzy subset corresponding to the temperature error e; or

According to the membership function of the fuzzy subset corresponding to the temperature error ec, the corresponding fuzzy set EC is obtained;

Wherein, the membership function is a trigonometric function or a Gaussian membership function, and FIG. 2 and FIG. 4 respectively show the membership function corresponding to the temperature error e and the membership function corresponding to the temperature error change ec.

Step S13, according to the temperature error fuzzy set E and the temperature error change fuzzy set EC, query the pre-generated △Kp law table, △Ki law table, △Kd law table, and obtain the fuzzy sets of △Kp, △Ki, △Kd , the fuzzy set of △Kp, △Ki, △Kd is one of positive big PB, positive middle PM, positive small PS, zero Z, negative small NS, negative middle NM and negative big ND;

It further includes the step of generating the △Kp law table, △Ki law table, and △Kd law table in advance, wherein E, EC, △Kp, △Ki, △Kd have the following mapping relationship:

E×EC→ΔKp×ΔKi×ΔKd

In the △Kp law table, △Ki law table, and △Kd law table, corresponding to each domain value of E and EC, the △Kp, △Ki, △Kd all have a definite domain value, Among them, the △Kp law table, △Ki law table, and △Kd law table can be shown in Fig. 7, Fig. 8 and Fig. 9 respectively.

It can be understood that, in other embodiments, the fuzzy sets of ΔKp, ΔKi, and ΔKd corresponding to the current temperature error fuzzy set E and the temperature error change fuzzy set EC can also be obtained through real-time calculation.

It can be understood that the fuzzy inference relationship composed of E and EC two inputs is:

If E=A and EC=B, so Kx=C; among them, A, B, and C are among positive big PB, positive middle PM, positive small PS, zero Z, negative small NS, negative middle NM and negative big ND one;

Using the mamdani calculation method, the law table of △Kp, △ki, △kd can be obtained directly.

For example, in one example, the fuzzy sets of △Kp, △Ki, △Kd corresponding to E and EC can be obtained in the following way:

The system fuzzy controller has two inputs and three outputs, and its mapping relationship is:

E×EC→Kpf×Kif×Kdf

Each of the above parameters is the fuzzy quantity corresponding to the output and input.

Its fuzzy relationship:

R＝Y _ij [E _i ×EC _j ×Kx _ij ]

Formula: Kx is Kpf, Kif, Kdf.

Then the membership function of R is:

When e, ec input is fuzzy into fuzzy sets E, EC, the output fuzzy control quantity is Kx. Its fuzzy reasoning is:

K _x ＝(E×EC)×R

Therefore, the membership function of K is:

Step S14, performing defuzzification calculation according to the fuzzy sets of ΔKp, ΔKi, ΔKd to obtain Kp, Ki, Kd values;

Defuzzifying the fuzzy sets of ΔKp, ΔKi, and ΔKd to obtain corresponding domain values;

Multiply the domain value corresponding to △Kp, △Ki, △Kd by the quantization factor of the output variable to obtain the Kp, Ki, Kd value, and the output quantization factor is based on the actual domain of △Kp, △Ki, △Kd The relationship between fuzzy domain of discourse is obtained.

In an example, the defuzzification calculation can also be realized by the weighted average method, for example, the calculation can be performed by the following formula:

Where z is a variable and is integrated within the domain of discourse. Kc is kp, ki, kd.

Step S15: Calculate and obtain PID control parameters according to the Kp, Ki, and Kd values, and control the heater according to the PID control parameters so that the difference between the current cabinet temperature T2 and the cabinet external temperature T1 is maintained within a predetermined range ( Such as within ±3°C); by continuously obtaining the current corresponding Kp, Ki, and Kd values, the system can stably adjust the temperature in the cabinet. Among them, calculating and obtaining PID control parameters through Kp, Ki, and Kd values is a very mature technology, and will not be described in detail here.

Step S16, when the humidity H2 in the current cabinet is greater than a starting threshold, control the compressor to start to dehumidify the inside of the terminal box. In one example, the starting threshold is 50%.

Since the dehumidification process of the dehumidifier reduces the ambient temperature in the cabinet, the control of humidity and temperature can have a mutual monitoring effect.

Repeat the preceding steps to prevent condensation in the power box.

As shown in FIG. 10 , it shows a detailed flowchart of an embodiment of an anti-condensation control method for a power equipment box provided by the present invention. In this embodiment, information such as temperature T1 outside the cabinet, temperature T2 inside the cabinet, and temperature H2 inside the cabinet are obtained through sensors, and the temperature change ΔT1 outside the cabinet is obtained by calculation, so as to determine whether the external environment temperature rises, falls, or is stable, and then Operate under the temperature condition of anti-condensation.

Among them, it is necessary to refer to the actual error value and error change value to quantify the corresponding domain. The temperature error e of the process system normally ranges from 0° to 100°. However, when |e|>10°, directly use the existing PID control. When |e|<10°, PID parameters are obtained by fuzzy control self-tuning. When the following situation occurs, the error range needs to be judged first; among them, T1, T2, H1, and H2 are the temperature outside the cabinet, the temperature inside the cabinet, the humidity outside the cabinet, and the humidity inside the cabinet, and e(k) is the kth sampling input Error, ec(k) is the input error change of the kth sampling. Then use the algorithm to judge the environmental temperature change and determine the anti-condensation measures, because in the cooling or low temperature environment and the heating or high temperature environment, different calculation methods can be used to obtain the values of e and ec, and then fuzzy e and ek , and perform fuzzy tuning to obtain △Kp, △Ki, △Kd; calculate the corresponding kp, ki and kd values according to the △Kp, △Ki, △Kd, so as to control the output of PID and adjust the heater; at the same time, according to The value of H2 determines whether the compressor needs to be activated for dehumidification.

Implement the present invention, have following beneficial effect:

The embodiment of the present invention provides an anti-condensation control method for a power equipment box, which can keep the temperature difference inside and outside the power equipment box within a predetermined range through the fuzzy control method, and at the same time perform dehumidification treatment in combination with the humidity in the cabinet, which can be very good It can effectively prevent the generation of condensation, and at the same time reduce the engineering quantity and risk of the transformation of the cabinet, and facilitate maintenance.

Although the present invention has been disclosed as above with preferred embodiments, they are not intended to limit the present invention. Any skilled person can make various changes or modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be defined by the protection scope of the claims of the present application.

Claims (6)

1. An electric equipment box anti-condensation control method, is characterized in that, comprises the steps: Obtain at least the temperature T2 inside the cabinet, the temperature T1 outside the cabinet and the humidity H2 inside the cabinet in real time through a variety of sensors; Judging the situation of the external environment temperature in different regions, calculating and obtaining the current temperature error e and temperature error change ec according to the temperature T2 inside the cabinet and the temperature T1 outside the cabinet; The temperature error e and the temperature error change ec are fuzzified to obtain the fuzzy set E corresponding to the temperature error e and the fuzzy set EC corresponding to the temperature error change ec, wherein the fuzzy set is Zhengda PB, Zhengzhong PM, One of positive small PS, zero Z, negative small NS, negative medium NM and negative large ND; According to the temperature error fuzzy set E and the temperature error change fuzzy set EC, query the pre-generated △Kp law table, △Ki law table, △Kd law table, and obtain the fuzzy sets of △Kp, △Ki, △Kd, the said The fuzzy set of △Kp, △Ki, △Kd is one of positive big PB, positive middle PM, positive small PS, zero Z, negative small NS, negative middle NM and negative big ND; Perform defuzzification calculations according to the fuzzy sets of ΔKp, ΔKi, and ΔKd to obtain Kp, Ki, and Kd values; Calculate and obtain PID control parameters according to the Kp, Ki, and Kd values, and control the heater according to the PID control parameters, so that the difference between the current cabinet temperature T2 and the cabinet external temperature T1 remains within a predetermined range; When the humidity H2 in the current cabinet is greater than a startup threshold, the compressor is controlled to start to dehumidify the interior of the terminal box. 2. A kind of anti-condensation control method of electric equipment box as claimed in claim 1, is characterized in that, carry out fuzzy processing to described temperature error e and temperature error change ec, obtain the fuzzy set corresponding to described temperature error e The steps of the fuzzy set EC corresponding to E and the temperature error change ec are as follows: According to the relationship between the actual universe of the temperature error e and the fuzzy universe, the input quantization factor ke is obtained, the actual value of the temperature error e is multiplied by the input quantization factor ke, the quantization input value of the temperature error e is obtained, and carried out Fuzzy processing to obtain the corresponding fuzzy set E; According to the relationship between the actual universe of the temperature error change ec and the fuzzy universe, the input quantization factor kec is obtained, and the actual value of the temperature error change ec is multiplied by the input quantization factor kec to obtain the quantized input value of the temperature error change ec , and perform fuzzy processing to obtain the corresponding fuzzy set EC. 3. A kind of electric equipment box anti-condensation control method as claimed in claim 1, is characterized in that, described fuzzification processing is specifically as follows: Obtain the corresponding fuzzy set E according to the membership function of the fuzzy subset corresponding to the temperature error e; or According to the membership function of the fuzzy subset corresponding to the temperature error ec, the corresponding fuzzy set EC is obtained; Wherein, the membership function is a trigonometric function or a Gaussian membership function. 4. A kind of anti-condensation control method for electric equipment box as claimed in claim 3, it is characterized in that, further comprises the step of generating △Kp law table, △Ki law table, △Kd law table in advance, wherein, E, EC , △Kp, △Ki, △Kd have the following mapping relationship: E×EC→ΔKp×ΔKi×ΔKd In the ΔKp rule table, ΔKi rule table, and ΔKd rule table, corresponding to each domain value of E and EC, the ΔKp, ΔKi, and ΔKd all have a definite domain value. 5. The anti-condensation control method for power equipment boxes according to any one of claims 1 to 4, characterized in that Kp is obtained by performing defuzzification calculations according to the fuzzy sets of ΔKp, ΔKi, and ΔKd , Ki, Kd value steps are as follows: Defuzzifying the fuzzy sets of ΔKp, ΔKi, and ΔKd to obtain corresponding domain values; Multiply the domain value corresponding to △Kp, △Ki, △Kd by the quantization factor of the output variable to obtain the Kp, Ki, Kd value, and the output quantization factor is based on the actual domain of △Kp, △Ki, △Kd The relationship between fuzzy domain of discourse is obtained. 6 . The anti-condensation control method for a power equipment box according to claim 5 , wherein the activation threshold is 50%, and the predetermined range is ±3°C. 7 .